Further thinking : while the real leather one might also be tempting, I'm less interested in those cases with which you have to slide the reader in, since it adds extra height and makes it more difficult for fingers to reach the screen, especially near the borders.
It has been my experience on Kobo Touch with the luxe cover (reading lamp model) anyway.

Plus, I'm afraid this leather one would be a bit too much on the heavy side for my taste, and on the thick side for my handbag's.

Plastic shell and overall material is definitely less sexy on this slimfit case but, provided it has sleep function, I will still probably go for it.